zirconium oxide OR C028541
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In this work, a hybrid organic-inorganic adsorbent based on polyelectrolyte copolymers of poly(4-vinylbenzyl trimethylammonium chloride-co-2-hydroxyethyl methacrylate) microspheres mixed with a hydrous zirconium oxide phase were applied to remove arsenic species from aqueous solutions. The hybrid adsorbent was synthesized in a two-step procedure: first, the polymeric microspheres were obtained through emulsion radical copolymerization, and then, the microspheres were impregnated with a zirconium oxide precursor followed by the subsequent sol-gel reaction. The purpose of this hybrid material was to combine properties of each component in the interaction with arsenic oxoanions and compare its performance with commercial adsorbents. The polymer hybrid microspheres were shown to remove arsenate, and the presence of the inorganic phase also allowed for the removal of arsenite. The hybrid adsorbent exhibited arsenic sorption independent of pH, is able to regenerate, displays fast kinetics and has the ability to reduce arsenic concentration in treated water below 10 μg L-1 even in real samples with an initial concentration as high as 380 μg L-1.
Zirconium doped mixed nanodispersive oxides of Ti and Fe were prepared by homogeneous hydrolysis of sulphate salts with urea in aqueous solutions. Synthesized nanodispersive metal oxide hydroxides were characterised as the Brunauer-Emmett-Teller (BET) surface area and Barrett-Joiner-Halenda porosity (BJH), X-ray diffraction (XRD), infrared (IR) spectroscopy, scanning electron microscopy (SEM) with energy-dispersive X-ray (EDX) microanalysis, and acid-base titration. These oxides were taken for an experimental evaluation of their reactivity with sulphur mustard (chemical warfare agent HD or bis(2-chloroethyl)sulphide). The presence of Zr(4+) dopant tends to increase both the surface area and the surface hydroxylation of the resulting doped oxides in such a manner that it can contribute to enabling the substrate adsorption at the oxide surface and thus accelerate the rate of degradation of warfare agents. The addition of Zr(4+) to the hydrolysis of ferric sulphate with urea shifts the reaction route and promotes formation of goethite at the expense of ferrihydrite. We discovered that Zr(4+) doped oxo-hydroxides of Ti and Fe exhibit a higher degradation activity towards sulphur mustard than any other yet reported reactive sorbents. The reaction rate constant of the slower parallel reaction of the most efficient reactive sorbents is increased with the increasing amount of surface base sites.
- MeSH
- adsorpce MeSH
- chemická válka MeSH
- chemické látky znečišťující vodu analýza MeSH
- čištění vody metody MeSH
- difrakce rentgenového záření MeSH
- hydrolýza MeSH
- mikroskopie elektronová rastrovací metody MeSH
- nanotechnologie metody MeSH
- oxidy chemie MeSH
- spektrofotometrie infračervená metody MeSH
- titan chemie MeSH
- yperit analýza chemie MeSH
- železité sloučeniny chemie MeSH
- zinek MeSH
- zirkonium chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Separation of biologically active peptides was performed on polybutadiene (PBD) and polystyrene (PS) reversed phases based on zirconium dioxide. ZrO2 as an alternative carrier to silicagel offers ion-exchange interactions, which are useful for separation of ionizable compounds. The parameters like buffer concentration and pH, the amount of organic modifier and temperature affected separation of nonapeptides. The retention characteristics (retention factor, resolution, peak symmetry, separation efficiency) were investigated. The systems consisting of acetonitrile and phosphate buffer of basic pH were found suitable for separation of vasopressin-related peptides.
Cílem práce je popsat neobvyklou kazuistiku pacienta s diabetem 1. typu, kterému bylo po vyloučení primárně stabilních titanových implantátů (v odstupu několika týdnů po lege artis provedené operaci) na základě zjištění mnohočetné alergie na kovy, včetně titanu, provedeno ošetření keramickými implantáty na bázi oxidu zirkoničitého (ZrO2). Následně byl pacientovi zhotoven imediátní fixní dlahovací kompozitní můstek. Po šesti měsících byla protetická práce sejmuta, přeměřena stabilita vhojených implantátů a bylo provedeno definitivní ošetření celokeramickým fixním dlahovacím můstkem ze zirkoničité keramiky. Tuto ojedinělou kazuistiku bude velmi obtížné potvrdit dostatečně četným randomizovaným souborem, vzhledem k velké vzácnosti, dosud ve světové literatuře nepopsané. Pokud však lze tvořit závěry z tohoto ojedinělého případu, ošetření pacienta s alergií na titan a diabetem 1. typu implantátem zirkoniumoxidu se jeví jako možná terapeutická alternativa.
The objective of the work was to describe an unusual case report of a patient with Type 1 diabetes, who eliminated the primarily stable titanium implants (within the time lapse of several weeks after lege artis - performed operation) due to multiple allergy to metals and was later treated with ceramic implants on the basis of zirconium oxide (ZrO2). Later on the patient was treated with immediate fixed splint composite bridge. Six months later the prosthetic work was taken off, stability of the healed implants was measured and a final treatment was performed using an all-ceramic fixed splint bridge from a zirconium ceramic. This rare case history will be difficult to verify by sufficiently randomized group in view of the scarceness as indicated by lacking available world literature. If such conclusion may be drawn from this rare case, the treatment of a patient with allergy to titanium and Type 1 diabetes with zirconium oxide implants appear to be a possible therapeutic alternative.
- MeSH
- alergie komplikace MeSH
- diabetes mellitus 1. typu komplikace MeSH
- lidé MeSH
- zirkonium terapeutické užití MeSH
- zubní implantáty využití MeSH
- zubní materiály chemie klasifikace kontraindikace MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- kazuistiky MeSH
In this work, we report for the first time on the use of melt spun glass-forming alloys - Ti75Zr10Si15 (TZS) and Ti60Zr10Si15Nb15 (TZSN) - as substrates for the growth of anodic oxide nanotube layers. Upon their anodization in ethylene glycol based electrolytes, highly ordered nanotube layers were achieved. In comparison to TiO2 nanotube layers grown on Ti foils, under the same conditions for reference, smaller diameter nanotubes (~116nm for TZS and ~90nm for TZSN) and shorter nanotubes (~11.5μm and ~6.5μm for TZS and TZSN, respectively) were obtained for both amorphous alloys. Furthermore, TEM and STEM studies, coupled with EDX analysis, revealed a double-wall structure of the as-grown amorphous oxide nanotubes with Ti species being enriched in the inner wall, and Si species in the outer wall, whereby Zr and Nb species were homogeneously distributed.
